Intel Discloses More Details About Itanium "Poulson" Microprocessor

Intel Corp. has disclosed more features and peculiarities about its next-generation Itanium processor code-named Poulson at the Hot Chips conference. The company continues to remain committed to the Itanium architecture, but promises to add features of Poulson to future Intel Xeon processors.

The Itanium "Poulson" 12-wide issue microprocessor has eight multi-threaded cores with new micro-architecture and a new version of Hyper-Threading technology, a ring-based system interface and combined 50MB cache on the die. Among the key core architecture improvements, Intel names new floating point pipeline, new data ant instruction popes, new instruction buffer and doubled max execution width (6 to 12). The innovations allow Intel to increase performance per watt, increase instruction throughput and boosted RAS coverage.

There are three key feature areas of Poulson. The first is Intel Instruction Reply Technology, which is a major RAS enhancement. This is the first Intel processor with Instruction Replay RAS capability, and it utilizes a new pipeline architecture to expand error detection in order to capture transient errors in execution. Upon error detection, instructions can then be re-executed from the instruction buffer queue to automatically recover from severe errors to improve resiliency.

The same instruction buffer capability also enables the second new feature, an improved Hyper-Threading Technology. It supports performance enhancement with Dual Domain Multithreading support, which enables independent front and backend pipeline execution to improve multi-thread efficiency. As EPIC architecture is already known for its highly parallel nature, this enhancement will help take Poulson’s overall parallelism to the next level.

Lastly, Poulson is adding new instructions in four key areas. First there are new Integer operations (mpy4, mpyshl4, clz). In support of the higher parallelism and multithreading capabilities, there is expanded Data Access Hints (mov dahr), Expanded Software Prefetch (ifetch.count) and Thread Control (hint@priority). These new instructions lay the foundation for the Itanium architecture to grow with future needs.

High speed links of the new chips allow for peak processor-to-processor bandwidth of up to 128GB/s and memory bandwidth of up to 45GB/s, according to Intel.

"While Itanium customers are always interested in coming attractions, it’s also worthwhile for Intel Xeon Server customers to also keep an eye on the evolution of Itanium, as many features originally introduced on Itanium often waterfall down to subsequent generations of Xeon CPU chips. Remember that Poulson, like the current Intel Itanium 9300 processor shares many common platform ingredients with Xeon, including the Intel QuickPath and scalable memory interconnects, the Intel 7500 scalable memory buffer and DDR3, and the Intel 7500 chipset," said Pauline Nist, a spokeswoman at Intel.

Intel Itanium "Poulson" chip contains 3.1 billion transistors, is made using 32nm process technology and will measure by 18.2*29.9mm, which equals to 545.8mm2 die size, which is smaller compared to previous-generation Itanium "Tukwila" that is 700mm2 large.

"As you can see, most of these features are designed to take full advantage of the 8 core, 12-wide issue architecture by enabling the maximum amount of parallel execution. Poulson is on track for 2012 delivery (if you attended HP Discover you may have had a chance to actually see an active Poulson system!) and the follow-on future Kittson processor is under development," added Ms. Nist.